<template>
  <div>
    <div class="shopcart">
      <div class="content" @click="toggleList">
        <div class="content-left">
          <div class="logo-wrapper">
            <div class="logo" :class="{'highlight': totalCount > 0}">
              <i class="icon-shopping_cart"></i>
            </div>
            <div class="num" v-show="totalCount > 0">{{ totalCount }}</div>
          </div>
          <div class="price" :class="{'highlight': totalPrice > 0}">￥{{ totalPrice }}</div>
          <div class="desc">另需配送费￥{{ deliveryPrice }}元</div>
        </div>
        <div class="content-right">
          <div class="pay" :class="payClass" @click.stop.prevent="pay">{{ payDesc }}</div>
        </div>
      </div>

      <div class="ball-container">
        <div v-for="(ball, index) in balls" :key="index">
          <transition name="drop"
                      @before-enter="beforeDrop"
                      @enter="dropping"
                      @after-enter="afterDrop">
            <div class="ball" v-show="ball.show">
              <div class="inner inner-js"></div>
            </div>
          </transition>
        </div>
      </div>

      <transition name="fold">
        <div class="shopcart-list" v-show="listShow">
          <div class="list-header">
            <h1 class="title">购物车</h1>
            <span class="empty" @click="empty">清空</span>
          </div>
          <div class="list-content" ref="listContent">
            <ul>
              <li class="food" v-for="(food, index) in selectFoods" :key="index">
                <span class="name">{{ food.name }}</span>
                <div class="price">
                  <span>￥{{ food.price * food.count }}</span>
                </div>
                <div class="cartcontrol-wrapper">
                  <m-cartcontrol :food="food"></m-cartcontrol>
                </div>
              </li>
            </ul>
          </div>
        </div>
      </transition>

    </div>

    <transition name="fade">
      <div class="list-mask" v-show="listShow" @click="hideList"></div>
    </transition>
  </div>
</template>

<script type="text/ecmascript-6">
import BScroll from 'better-scroll';
import mCartcontrol from 'components/m-cartcontrol/m-cartcontrol';

export default {
  props: {
    selectFoods: {
      type: Array,
      default () {
        return [];
      }
    },
    deliveryPrice: {
      type: Number,
      default: 0
    },
    minPrice: {
      type: Number,
      default: 0
    }
  },

  data () {
    return {
      balls: [
        {show: false},
        {show: false},
        {show: false},
        {show: false},
        {show: false}
      ],
      dropBall: [],
      fold: true
    };
  },

  computed: {
    totalPrice () {
      let total = 0;
      this.selectFoods.forEach((food) => {
        total += food.price * food.count;
      });
      return total;
    },

    totalCount () {
      let count = 0;
      this.selectFoods.forEach((food) => {
        count += food.count;
      });
      return count;
    },

    payDesc () {
      if (this.totalPrice === 0) {
        return `￥${this.minPrice}元起送`;
      } else if (this.totalPrice < this.minPrice) {
        return `还差￥${this.minPrice - this.totalPrice}元起送`;
      } else {
        return '去结算';
      }
    },

    payClass () {
      if (this.totalPrice < this.minPrice) {
        return 'not-enough';
      } else {
        return 'enough';
      }
    },

    listShow () {
      /* if (!this.totalCount) {
                        this.fold = true;
                      } else {
                        return !this.fold;
                      } */
      let show = !this.fold;
      if (show) {
        this.$nextTick(() => {
          this._recountListContent();
        });
      }
      return show;
    }
  },

  methods: {
    _recountListContent () {
      if (!this.scroll) {
        this.scroll = new BScroll(this.$refs.listContent, {
          click: true
        });
      } else {
        // listShow 是不断变化的 避免重新 new
        // refresh 当 DOM 结构发生变化时，重新计算 betterScroll
        this.scroll.refresh();
      }
    },

    pay () {
      if (this.totalPrice < this.minPrice) {
        return;
      }
      window.alert(`支付${this.totalPrice}元`);
    },

    hideList () {
      this.fold = true;
    },

    empty () {
      this.selectFoods.forEach((food) => {
        food.count = 0;
      });
    },

    toggleList () {
      if (!this.totalCount) {
        return;
      }
      this.fold = !this.fold;
    },

    drop (el) {
      for (let i = 0; i < this.balls.length; i++) {
        let ball = this.balls[i];
        if (!ball.show) {
          ball.show = true;
          ball.el = el;
          this.dropBall.push(ball);
          return;
        }
      }
    },

    beforeDrop (el) {
      let count = this.balls.length;
      while (count--) {
        let ball = this.balls[count];
        if (ball.show) {
          // getBoundingClientRect 元素相对于视口的位置 浏览器接口
          let rect = ball.el.getBoundingClientRect();
          let x = rect.left - 32;
          let y = -(window.innerHeight - rect.top - 22);
          el.style.display = '';
          el.style.webkitTransform = `translate3d(0, ${y}px, 0)`;
          el.style.transform = `translate3d(0, ${y}px, 0)`;
          let inner = el.getElementsByClassName('inner-js')[0];
          inner.style.webkitTransform = `translate3d(${x}px, 0, 0)`;
          inner.style.transform = `translate3d(${x}px, 0, 0)`;
        }
      }
    },
    dropping (el, done) {
      // done 告诉 vue 动画结束
      /* 触发浏览器重绘 */
      /* eslint-disable no-unused-vars */
      let rf = el.offsetHeight;
      this.$nextTick(() => {
        el.style.webkitTransform = 'translate3d(0, 0, 0)';
        el.style.transform = 'translate3d(0, 0, 0)';
        let inner = el.getElementsByClassName('inner-js')[0];
        inner.style.webkitTransform = 'translate3d(0, 0, 0)';
        inner.style.transform = 'translate3d(0, 0, 0)';

        el.addEventListener('transitionend', done);
      });
    },
    afterDrop (el) {
      let ball = this.dropBall.shift();
      if (ball) {
        ball.show = false;
        el.style.display = 'none';
      }
    }
  },

  components: {
    mCartcontrol
  }
};
</script>

<style scoped lang="stylus" rel="stylesheet/stylus">
  @import "../../common/stylus/mixin.styl";
  .shopcart {
    position: fixed
    left: 0
    bottom: 0
    z-index 50
    width 100%
    height: 48px

    .content {
      display flex
      background #141d27
      font-size 0
      color: rgba(255, 255, 255, .4)
      .content-left {
        flex 1

        .logo-wrapper {
          display inline-block
          position relative
          top: -10px
          margin: 0 12px
          padding 6px
          width: 56px
          height: 56px
          box-sizing: border-box
          vertical-align: top
          border-radius: 50%
          background #141d27
          .logo {
            width 100%
            height 100%
            border-radius 50%
            background #2b343c
            text-align center
            &.highlight {
              background rgb(0, 160, 220)
              .icon-shopping_cart {
                color: #fff
              }
            }
            .icon-shopping_cart {
              font-size 24px
              color: #80858a
              line-height 44px
            }
          }
          .num {
            position absolute
            top 0
            right 0
            width 24px
            height 16px
            line-height 16px
            text-align center
            border-radius 16px
            font-weight 700
            font-size 9px
            color #fff
            background rgba(240, 20, 20, 1)
            box-shadow 0 4px 8px 0 rgba(0, 0, 0, .4)
          }
        }
        .price {
          display inline-block
          padding-right 12px
          vertical-align top
          margin-top 12px
          line-height 24px
          box-sizing border-box
          border-right 1px solid rgba(255, 255, 255, .4)
          font-size 16px
          font-weight 700
          &.highlight {
            color #fff
          }
        }
        .desc {
          display inline-block
          vertical-align top
          margin 12px 0 0 12px
          line-height 24px
          font-size 10px
        }
      }
      .content-right {
        flex: 0 0 105px
        width 105px
        .pay {
          height 48px
          line-height 48px
          text-align center
          font-size 12px
          font-weight 700
          background #2b333b
          &.not-enough {
            background #2b333b
          }
          &.enough {
            background #00b43c
            color #fff
          }
        }
      }
    }

    .ball-container {
      .ball {
        position fixed
        left 32px
        bottom 22px
        z-index 200
        &.drop-enter-active {
          transition all .4s cubic-bezier(.43, -0.65, .71, -0.02)
          .inner {
            width 16px
            height 16px
            border-radius 50%
            background rgb(0, 160, 220)
            transition all .4s linear
          }
        }
      }
    }

    .shopcart-list {
      position absolute
      top 0
      left 0
      z-index -1
      width 100%

      transition all .5s
      transform translate3d(0, -100%, 0)
      &.fold-enter, &.fold-leave-active {
        transform translate3d(0, 0, 0)
      }
      .list-header {
        height 40px
        line-height 40px
        padding 0 18px
        background #f3f5f7
        border-bottom 1px solid rgba(7, 17, 27, 0.1)
        .title {
          float left
          font-size 14px
          color: rgb(7, 17, 27)
        }
        .empty {
          float right
          font-size 12px
          color rgb(0, 160, 220)
        }
      }
      .list-content {
        padding 0 18px
        max-height 217px
        background #fff
        overflow hidden
        .food {
          position relative
          padding 12px 0
          box-sizing border-box
          border-1px(rgba(7, 17, 27, .1))

          .name {
            line-height 24px
            font-size 14px
            color rgb(7, 17, 27)
          }
          .price {
            position absolute
            right 90px
            bottom 12px
            line-height 24px
            font-size 14px
            font-weight 700
            color rgb(240, 20, 20)
          }
          .cartcontrol-wrapper {
            position absolute
            right 0
            bottom 6px
          }
        }
      }
    }
  }

  .list-mask {
    position fixed
    top 0
    left 0
    width 100%
    height 100%
    z-index 40
    backdrop-filter blur(10px)
    opacity 1
    background rgba(7, 17, 27, .6)
    transition all .5s
    &.fade-enter, &.fade-leave-active {
      opacity 0
      background rgba(7, 17, 27, 0)
    }
  }
</style>
